soc/intel/braswell: fix PCI resource PMAX/PLEN values

Without PMAX correctly set, the calculation for PLEN is incorrect,
leading to a Windows BSOD on boot.  Correct PMAX using code from
Baytrail SoC, setting PMAX to (CONFIG_MMCONF_BASE_ADDRESS - 1).

Test: Boot Windows 10 on google/edgar without BSOD.

Change-Id: I4f2f4a0ff3a285826709f9eaafa40b0bf0cafb83
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/24985
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/braswell/acpi/southcluster.asl

@@ -173,6 +173,7 @@ Method (_CRS, 0, Serialized)
 
 	/* TOLM is BMBOUND accessible from IOSF so is saved in NVS */
 	Store (\TOLM, PMIN)
+	Store (Subtract(CONFIG_MMCONF_BASE_ADDRESS, 1), PMAX)
 	Add (Subtract (PMAX, PMIN), 1, PLEN)
 
 	Return (MCRS)